A Zn(II)2Cys6 transcription factor VdRgt1 affects microsclerotia development, virulence, and glucose utilization in the smoke tree wilt fungus Verticillium dahliae
Results indicate that VdRgt1 is an important regulator in V. dahliae, coordinating hyphal development, the timing of microsclerotia development and melanin accumulation, carbon and energy metabolism, stress adaptation, and virulence.
Abstract
Verticillium dahliae is a soil-borne vascular pathogen with a broad host range and the ability to survive in soil for extended periods through the formation of stress-resistant microsclerotia. It poses a major challenge to disease management and frequently causes severe Verticillium wilt in smoke tree (Cotinus coggygria) in China. Zn(II)2Cys6 transcription factors (TFs) represent a major class of fungal regulators and are involved in various biological processes, including primary and secondary metabolism, stress adaptation, and pathogenesis. In this study, we found that the deletion of VdRgt1, which belongs to Zn(II)2Cys6 TF, led to abnormal hyphal morphology, reduced vegetative growth, markedly decreased conidial production, and altered timing of microsclerotia development and melanin accumulation. Additionally, the ΔVdRgt1 mutant exhibited significantly reduced virulence and impaired colonization of C. coggygria. Transcriptome analysis indicated that VdRgt1 is involved in the regulation of carbohydrate and energy metabolism. Consistently, the ΔVdRgt1 mutant exhibited reduced ATP levels, and RT-qPCR supported a role for VdRgt1 in glucose-responsive gene regulation. Collectively, these results indicate that VdRgt1 is an important regulator in V. dahliae, coordinating hyphal development, the timing of microsclerotia development and melanin accumulation, carbon and energy metabolism, stress adaptation, and virulence.
Findings underscore a significant role for VdOMO in siderophore-associated iron acquisition, fungal development, stress adaptation, and the early stages of host colonization in V. dahliae.
Yusha Du, Lixinyu Sun, Kang-Wei Xie et al.· Frontiers in Plant Science· 0 citations
It is demonstrated that VdPRMT1 is required for normal fungal development and full virulence in V. dahliae, and suggested that arginine methylation may contribute to pathogenicity through regulation of RNA processing-related pathways.
It is demonstrated that MrFTRP1 exerts a dual-regulatory functioning as a positive regulator of conidiation and pathogenesis but a negative regulator of environmental stress tolerance, which expands the understanding of the regulatory diversity within the C6 TF family and identifies him as a promising target for the genetic improvement of mycoinsecticides.
Chentian Jiang, Hao Wu, You-Gui Tong et al.· Journal of Invertebrate Path...· 0 citations
The soil-borne fungal pathogen Verticillium dahliae (V. dahliae) is the causal agent of Verticillium wilt (VW), a vascular disease that severely threatens global cotton production. Although cell wall lignification represents a cornerstone of plant immunity, the precise regulatory circuits that bridge this structural reinforcement with Verticillium dahliae resistance in cotton have yet to be fully elucidated. Here, we demonstrate that the NAC transcription factor GhNAC043 is a key positive regulator of this defense. GhNAC043 expression was rapidly induced upon V. dahliae infection. Silencing GhNAC043 in cotton compromised resistance, reducing lignin accumulation and downregulating lignin biosynthesis genes. Conversely, heterologous overexpression of GhNAC043 in Arabidopsis enhanced VW tolerance. We further identified GhBPM2 as a nuclear interaction partner of GhNAC043. Profiling of the transcriptome demonstrated that the GhNAC043-GhBPM2 module alters the expression profile of genes pivotal for jasmonic acid (JA) and abscisic acid (ABA) signal transduction. Collectively, these results highlight a previously unknown regulatory pathway in which the GhNAC043-GhBPM2 complex drives lignin deposition through the modulation of JA and ABA signaling, thereby fortifying cotton against VW infection.
Zhaoyuan Ba, Juyun Zheng, Ying Liu et al.· Plant physiology and biochem...· 0 citations
Verticillium dahliae is a destructive soil-borne fungus with a broad host range, and its persistence in soil complicates control. Current measures, mainly resistant cultivars and chemicals, are limited and environmentally risky, promoting biocontrol as a green alternative. Here, we investigated the biocontrol mechanisms of Bacillus velezensis L33a against V. dahliae JR2 in tomato. In vitro assays on PDA plates at 26°C for 9 d showed that L33a inhibited JR2 by 58.6%, caused hyphal malformation and disruption, and its volatile organic compounds suppressed pathogen growth. In pot experiments, tomato roots dipped in JR2 suspension (1 ×10⁶ CFU/mL) for 30 min at 7 d after transplanting and grown for 21 d achieved 60.9% control efficacy. Physiological assays indicated reduced peroxidase and catalase activities, while qPCR revealed that L33a alone upregulated JA signaling (SlJAZ1, SlMYC2, SlPI II) and antioxidant (SlCAT, SlAPX) genes, with further enhancement upon JR2 co-treatment. To track their interactions, we generated GFP-labeled JR2 and RFP-labeled L33a; dual fluorescence labeling showed that L33a endophytically colonized Arabidopsis thaliana roots and competed with JR2 for the same niche, correlating with reduced pathogen colonization. Integrated metabolomic and transcriptomic analysis further revealed that L33a treatment altered pathways related to ABC transporters, amino acid metabolism, cell wall integrity, and energy metabolism in JR2, with tyrosine metabolism significantly enriched at both levels. Collectively, these findings suggest that L33a is a promising biocontrol strain for green management of tomato Verticillium wilt.
The results suggest that TrcrtB and phytoene are critical for development, stress tolerance and pathogenicity of T. roseum and highlight the roles of TrcrtB and phytoene in the pathogenic fungus T. roseum.
